Colorectal cancer

Question 1

colorectal cancer is ___ leading cause of cancer mortality for males and the ______ leading cause for females

Answer 1

2nd

3rd

Question 2

What is the etiology and risk factors for colorectal cancer

Answer 2

• largely unknown
• incidence increases with age
• incidence increases with family history of cancer or people w crohns or ulcerative colitis & familial adenomatus polyps
• familial risk (relatives with colorectal cancer)
• hypothesized: high level of fat in diet increase synthesis of bile acids in liver which may be converted to potential carcinogens by bacteria flora
• bacteria organisms in particular suspected of converting bile acids to carcinogens their proliferation is enhanced by a high dietary level of refined sugar
• refined diets often contain reduced amount of vitamins A,C & E which may act as oxygen free radiacal scavengers

Question 3

90% of people who develop colorectal cancer are what age range?

Answer 3

50++

Question 4

suspected protective factor of colorectal cancer

Answer 4

• dietary fiber thought to increase stool bulk and therby dilutes & removes potential carcinogens
• reports also indicate that aspirin may protect against colorectal cancer

Question 5

colorectal cancer is commonly classified into ______

Answer 5

four tumor node metasis stages

Question 6

Major mnfts of colorectal cancer

Answer 6

• usually cancer of colon & rectum present for a long time before it produces symptoms
• bleeding is a highly significant early symptom (usually the one that causes person to seek medical care)
• other symptoms: changes in bowel habits, diarrhea & constipation & sometimes a sense of urgency or incomplete emptying of bowl
• pain is usually a late symptom

Question 7

screening and diagnosing colorectal cancer

Answer 7

• single most important prognostic indicator of colorectal cancer extent (stage) of tumor @ time of diagnosis challenge is to discover tumor at their earliest stage
• digital rectal exam & fecal occult blood test(usually done during routine px)
• digital rectal exams most helpful in detecting neoplasms of rectum
• colonoscopy recommended whenever a screening is positive

Question 8

treatment of colorectal cancer

Answer 8

only recognized treatment for cancer of the colon & rectum is surgical removal, preoperative radiation therapy may be used & has in some cases demonstrated increased 5 yr survival rates, post op chemotherapy may be used

Question 9

Stage 1 tumor (colorectal cancer)

Answer 9

limited to invasion of mucosal & submucosal layers of the colon, has a 5 yr survival rate of 80%-90%

Question 10

Stage II tumor (colorectal cancer)

Answer 10

• lymoh node negative tumor

- tumor inflitartes into but not through muscularis externa, 5 yr survival rate of 70-85%

Question 11

Stage III tumor (colorectal cancer)

Answer 11

invasion of the serosal layer and regional lymph node involvment, 5 yr survival rate is 40%-60%

Question 12

Stage 4 tumor (colorectal cancer)

Answer 12

• (metastatic)

- penetrate the serosa ir adjacent organs & have much poorer prognosis